Stimulation of total phenolics, L-DOPA and antioxidant activity through proline-linked pentose phosphate pathway in response to proline and its analogue in germinating fava beans (Vicia faba)

Shetty, Preethi; Atallah, Mokthar T; Shetty, Kalidas

doi:10.1016/s0032-9592(02)00257-1

Cited by 27 publications

(17 citation statements)

References 44 publications

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“…Anthraquinone analysis content was determined spectophotometrically, according to Schulte et al (1984). Total phenolic content was determined by the assay described by Shetty et al (2003).…”

Section: Analytical Techniquesmentioning

confidence: 99%

Increasing anthraquinone production by overexpression of 1-deoxy-d-xylulose-5-phosphate synthase in transgenic cell suspension cultures of Morinda citrifolia

et al. 2010

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A Morinda citrifolia cell line was obtained by overexpresion of 1-deoxy-D: -xylulose 5-phosphate synthase (DXS) from Catharanthus roseus, a key enzyme of the metabolic pathway of anthraquinones (AQs). This cell line increased AQs production by about 24% compared to the control cell line. This transgenic cell line which carries dxs cDNA isolated from Catharanthus roseus, was achieved by direct transformation of cell suspension cultures of M. citrifolia using a hypervirulent Agrobacterium tumefaciens strain. The effects of the overexpression of the dxs gene also resulted in increased levels of dxs mRNA transcripts and DXS activity compared to the control cell line. In addition, total phenolics and phenylalanine ammonia-lyase activity were evaluated and were significantly higher in the transgenic line than in controls.

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Section: Analytical Techniquesmentioning

confidence: 99%

Increasing anthraquinone production by overexpression of 1-deoxy-d-xylulose-5-phosphate synthase in transgenic cell suspension cultures of Morinda citrifolia

et al. 2010

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“…The addition of proline analogs is another way to stimulate the proline cycle, since they act as competitive inhibitors of proline dehydrogenase (PDH). It was previously shown that 200 lM of azetidine-2-carboxylic acid (A2C) enhanced total phenolics, proline, and G6PDH activity in Vicia faba (Shetty et al 2003). Thiazolidine-4-carboxylic acid (T4C), another proline analog, was found to affect proline metabolism in Hordeum vulgare, exhibiting different effects on turgid and wilted leaves (Elthon and Stewart 1984).…”

Section: Introductionmentioning

confidence: 99%

Stimulation of the proline cycle and anthraquinone accumulation in Rubia tinctorum cell suspension cultures in the presence of glutamate and two proline analogs

Perassolo

Quevedo

Giulietti

et al. 2010

Plant Cell Tiss Organ Cult

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Anthraquinone biosynthesis in Rubia tinctorum L. involves different metabolic routes. Chorismic acid, the end-product of the shikimate pathway, becomes the branch point between primary and secondary metabolism. It has been proposed that the proline cycle could be coupled with the pentose phosphate pathway (PPP), since the NADP ? generated by proline reduction from glutamate could act as a cofactor of the first enzymes of the PPP. This pathway generates erythrose-4-phosphate, the substrate of the shikimate pathway. The aim of the present work was to study the effect of the addition of glutamate and two proline analogs, azetidine-2-carboxylic acid and thiazolidine-4-carboxylic acid (T4C), on the PPP, the proline cycle, and anthraquinone production in R. tinctorum cell suspension cultures. The addition of 5 mM of glutamate enhanced both anthraquinone (up to 30%) and total phenolic content (12%), which correlated well with proline accumulation. Only the addition of 200 lM of T4C resulted in an increase in anthraquinone production, which was accompanied by a rise in the proline content. Neither the addition of glutamate nor proline analogs resulted in the induction of PPP, so this route was not a limiting factor as a carbon donor to the shikimate pathway.

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“…AQ content was determined spectrophotometrically according to Schulte et al (1984), and total phenolic content was determined according to Shetty et al (2003). In both cases, results are expressed per 1 g of fresh wt biomass (FW).…”

Section: Analytical Techniquesmentioning

confidence: 99%

“…Thus, by stimulating the proline cycle, it should be possible to increase the carbon flux through the PPP and towards the shikimate pathway, since its precursor, erythrose 4-phosphate, is the end-product of the PPP. Proline analogs have been used to enhance the proline cycle because, since they are competitive inhibitors of proline dehydrogenase (PDH), proline accumulates to overcome this inhibition (Shetty et al 2003;Yang and Shetty 1998).…”

Section: Introductionmentioning

confidence: 99%

Enhancement of anthraquinone production in Morinda citrifolia cell suspension cultures after stimulation of the proline cycle with two proline analogs

et al. 2011

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Synthesis of anthraquinones (AQs) involves the shikimate and 2-C-methyl-D-erythritol 4-phosphate pathways. The proline cycle is linked to the pentose phosphate pathway (PPP) to generate NADPH needed in the first steps of this pathway. The effect of two proline analogs, azetidine-2-carboxylic acid (A2C) and thiazolidine-4-carboxylic acid (T4C), were evaluated in Morinda citrifolia suspension cultures. Both analogs gave higher proline accumulation after 6 and 10 days (68 and 179% after 6 days with A2C at 25 and 50 μM, respectively, and 111% with T4C added at 100 μM). Induction of the proline cycle increased the AQ content after 6 days (~40% for 50 μM A2C and 100 μM T4C). Whereas A2C (50 μM) increased only AQ production, T4C also enhanced total phenolics. However, no induction of the PPP was observed with any of the treatments. This pathway therefore does not limit the supply of carbon skeletons to secondary metabolic pathways.

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Stimulation of total phenolics, L-DOPA and antioxidant activity through proline-linked pentose phosphate pathway in response to proline and its analogue in germinating fava beans (Vicia faba)

Cited by 27 publications

References 44 publications

Increasing anthraquinone production by overexpression of 1-deoxy-d-xylulose-5-phosphate synthase in transgenic cell suspension cultures of Morinda citrifolia

Increasing anthraquinone production by overexpression of 1-deoxy-d-xylulose-5-phosphate synthase in transgenic cell suspension cultures of Morinda citrifolia

Stimulation of the proline cycle and anthraquinone accumulation in Rubia tinctorum cell suspension cultures in the presence of glutamate and two proline analogs

Enhancement of anthraquinone production in Morinda citrifolia cell suspension cultures after stimulation of the proline cycle with two proline analogs

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